1. Field of the Invention
The disclosure relates generally to RAID (Redundant Arrays of Independent Disks) systems and setup methods thereof, and, more particularly to systems and setup methods thereof that integrate RAID 5 and RAID 1 architecture.
2. Description of the Related Art
Employment of disk arrays can improve access speed to disks and prevent data lost due to disk failure. Disk arrays integrate several disks into an array, used as a single disk. Data in a disk array is stripped and stored in different disks. During data access, related disks in the disk array can work simultaneously, reducing the data access time.
The technique for disk array is referred to as RAID, and configured in levels RAID 0 to RAID 5. In some RAID levels, in addition to data strips stored in different disks, parity information corresponding to data can be further calculated and stored in a specific disk of the disk array. If a disk storing one of the data strips fails, the data strip in the failed disk can be recovered according to the other data strips and the parity information.
FIG. 1 is a schematic diagram illustrating a conventional fault tolerance RAID 5 architecture. As shown in FIG. 1, disks D0˜Dn are selected as a group to create a RAID 5 architecture, in which data strips S0˜S2 are stored in different disks. It is understood that a strip size parameter must be configured during the creation of RAID 5 architecture, with data stripped and stored in different disks accordingly. Additionally, parity information P is stored in a specific disk.
Generally, an enterprise extends a storage system according to its own requirement. With advances in manufacturing technology and process, disk capacity has grown. Several disks having different sizes may be utilized in an enterprise. In conventional disk array technology, however, only a single RAID level can be applied, such that the capacity of each disk cannot be fully utilized. In FIG. 1, since disks D0˜Dn are selected to create a RAID 5 architecture, and disk D0 has minimum disk capacity, the disk capacity of disk D0 size in respective disks is selected to create the RAID 5 architecture. As shown in FIG. 1, since the disk size of respective disks are different, the remnant disk capacity R1 in disk D1 and remnant disk capacity R2 and R3 in disk Dn cannot be fully utilized.